Envelope Commissioning Guidelines and Standards
Envelope Commissioning Guidelines and Standards include ASHRAE 202P, NIBS Guideline 3, ASTM E2813, and LEEDv4 Enhanced Commissioning credit requirements. The December 2012 issue of Environmental Building News had a great article, Verifying Performance with Building Enclosure Commissioning, that did a great job outlining the differences between traditional mechanical Commissioning (Cx) (HVAC, lighting controls, plumbing, etc) and Building Enclosure Commissioning (BECx). Most of the following summary comes from that EBN article.
ASHRAE 202 Commissioning Process
The ASHRAE Standard, Commissioning Process for Buildings and Systems, defines building commissioning as an integrated process and stresses the importance of bringing the Commissioning Agent (CxA) on early in design. The standard is going through the process of becoming an ISO (International Organization for Standards) standard, which should lead to easier adoption into building codes across the country. Enclosure Commissioning is not specifically addressed in ASHRAE 202, but the general principles and approaches of the Cx process are well developed.
NIBS Guideline 3-2012 Building Enclosure Commissioning Process BECx
The 2012 National Institute of Building Sciences (NIBS) Guideline 3, Building Enclosure Commissioning Process, provides more specific information on hygrothermal performance (movement of moisture and heat through building assemblies) than the previous version from 2006. This Guideline is intended to be used with ASHRAE standards. NIBS has done a lot to develop and promote Enclosure (or Envelope) Commissioning in the US.
ASTM E2813 Building Enclosure Commissioning
The American Society for Testing and Materials (ASTM) E2813, Standard Practice for Building Enclosure Commissioning, outlines minimum requirements from the NIBS Guideline 3 process. It is a watered down version of the NIBS Guidelines, and is intended to make it easier and more cost effective for projects pursuing BECx on a limited budget. With the limited scope… the value of the service will be diminished… but some BECx is better than none at all!
LEEDv4 Enclosure Envelope Commissioning Requirements
Sadly the USGBC back-stepped when it comes to Building Envelope Commissioning guidelines. The first drafts of Version 4 (LEEDv4) included BECx as part of the Fundamental Commissioning prerequisite. This small action would have resulted in an explosion of BECx across the US, and meant many more building scientists educating teams on common moisture (and energy) pitfalls in building envelope design and construction. Current drafts of the proposed LEEDv4 include reference to NIBS Guideline 3-2006 (less emphasis on hygrothermal/BECx) and ASHRAE Guideline 0-2005 (The Commissioning Process), and only in the Enhanced Commissioning Credit (not prerequisite).
Under LEEDv4, f the Owner’s Project Requirements (OPR) include BECx, than at least a minimal form of BECx must be provided. However, there are no clear standards or protocols referenced to define the scope of a Building Enclosure Commissioning Agent. Perhaps future drafts or versions of LEED will directly reference NIBS Guideline 3-2012 or ASTM E2813, but it appears that isn’t in the cards for 2013.
A huge “THANK YOU” to Paula Melton and the rest of the gang at EBN for giving so much ink to Building Envelope Commissioning (BECx). BECx really is the wave of the future of high-performance buildings, and I’m grateful EBN is helping pave the way.
Another big “THANK YOU” to Kunjan Shah, the BECx Agent at Healthy Building Science, who continues to provide high-quality building science and enclosure commissioning services to our awesome clients.